Construction of blades for aircraft having gyratory wings



Dec. 6, 1960 CANT|N|EAU 2,963,094

CONSTRUCTION OF BLADES FOR AIRCRAFT HAVING GYRATORY WINGS Filed April 9,1956 Jam? (rzfazzbau,

United States Patent CONSTRUCTION OF BLADES FOR AIRCRAFI HAVING GYRATo YWINGS Jean Cantinieau, 40 Carrera de San Jeronimo, Madrid, Spain Thisinvention relates to the construction of supporting blades for aircrafthaving gyratory wings.

It is aimed to provide an improved construction which will combinelightness with suflicient and efficient distribution of strength andmass, preserving correct alignment of the centers of gravity of thecontours, the aerodynamic foci and the centers of section, as well aseconomy and ease of construction.

The invention applies especially to the frame construction of blades oflarge chord and size as well as'bla'des of small chord and size,attaining the same advantages as have the latter with feasibility ofconstruction with the weight per meter much less.

In the accompanying drawing and specification is disclosed by way ofexample, one preferred construction without limitative character.

In said drawing:

Figure 1 is a fragmentary plan view of the upper surface of the bladeframe, that is without the fabric cover, on the scale of approximatelyVs;

Figure 2 is a cross section taken on line 2-2 of Figure 1;

Figure 3 is a cross section taken on line 3-3 of Figure 1;

Figure 4 is a cross section taken on line 4-4 of Figure 1;

Figure 5 is a cross section taken on line 55 of Figure 1;

Figure 6 is a cross section taken on line 66 of Figure 1;

Figure 7 is a cross section taken on line 77 of Figure 1; and

Figure 8 is a cross section through a modified form of that shown inFigure 7.

Referring specifically to the drawing, the attack edge or nose A of theblade is a metallic counterweight preferably of steel of suitableprofile. Such nose is fitted throughout its length to a spar consistingof halves or sections B and C and serving as a girder.

Said spar is of light weight metal alloy such as Au 4 Cl with anodicprotection and its two shell halves or sections B and C are symmetricalas in Figures 2 and 3. Said two half shells leave a large central hollowportion H betwen them but adjacent both ends the sections along planarsurfaces are completely in contact so that the spar needs to be enlargedvery little, if at all, to carry out my invention, and as a result nodifficulty is experienced in fastening the improved blade in place on arotor. At the front the two half shells are fastened together as bybolts or rivets 1 passing through the nose and flanges 10 of thesections B and C interfitted in a groove 11 of the nose. At the rear,sections B and C are fastened together as by rivets or bolts 2 passingthrough flanges 12 as best shown in Figure 5.

By means of a series of rivets or bolts 3, and according to the lengthof blade desired, any number of stays 2,963,094 Patented Dec. 6, 1960ICC D are fastened to flanges 3' of the spar. The stays D are likewiseof light metal alloy and have a profile enlarged at V and have a foldededge. They form a skeletonized connecting means between the spar andstrut. The rear extremity, tapered, is riveted, bolted or otherwisefastened at 4 to a strut E arranged at the trailing edge, Figures 1 and6. Said strut E is made of light metal alloy and profiled in the form ofa very acute angle.

The bolts, pins or fastenings 2 and 3 alternate, respectively, in theupper and lower flanges 12 of the spar to facilitate assembling.

A fairing or faired member F of iron or light weight metal as requiredis provided at each end of the blade and is attached in any suitablemanner to the spar and strut, the opposite end of the blade beingfinished like the end shown at the top of Figure l to complete theperimeter of the blade and it is to be understood that the blade may beof any length desired.

It will be understood that by working on or proportioning the threeresistant elements, nose or counterweight, spar and strut, the weight ofthe blade can conveniently be centered and properly arranged anddistributed, keeping a few expansions due to the centrifugal force onsuch three elements, and in that way deformation of the structure in theplane of drag is successfully avoided.

It will also be realized that it is a simple matter to fix masses on theinside of the spar and center, proportion and distribute them veryadvantageously in combination with the end fairings F.

The blade is adapted to be fixed on the blade-carrying arm of a rotor bymeans of shafts which pass through holes 5 and 6 located adjacent oneend of the spar and which help to keep the two symmetrical sections Band C of the spar united.

The stresses of the counterweight nose A are borne by or carried over tothe said solid end portions of the spar by means of those fastenings 1nearest said portions. The stresses of the strut E are home or supported by the spar by means of skeleton members R of steel made in theshape of a V and fastened to each of them as shown as by rivets orbolts. Each of the arms of skeleton members R may have the cross sectionof either Figure 7 or Figure 8 according to the class of stress itbears.

The spaces G between the spar, the strut and the stays are filled with aspecial light material, such as Klegecell which can be perforated tolighten it even more. The skeleton members R will be hidden between theplates of said material.

Finally, over the filling material is applied a mastic cover ofsynthetic resin or other hard material, and the work is finished bycovering the entire blade with a fabric which imparts an aero-dynamicprofile.

The structure described admits of different variations in detail withinthe spirit and scope of the invention as defined by the appended claims.

I claim as my invention:

1. An aircraft blade having a spar serving as a girder and attachable atone end to a rotor, said spar being in sections producing a hollow spacebetween them and at said end being in flatwise contact with each other,a nose at the attacking edge of said spar, said nose and sections at theinner edge of said nose being in interfitted relation, fasteningssecuring the parts together at the zone of interfitting with their outersurfaces merging into one another, and means securing the spar sectionstogether at the edge opposite to said nose.

2. An aircraft blade having a spar serving as a girder, said spar beingin sections forming an enclosed hollow space between them and at one endbeing in flatwise contact with each other, a nose at the attacking edgeof said spar having a groove in its opposite edge, said sectionsextending into said groove and being in interfitted relation with thenose, fastenings securing the parts together at the zone ofinterfitting, said nose being a counterweight, a strut at the trailingedge of the blade, openwork stay means connecting the spar and strut, afilling contained in said open-work stay means, and fairings at the endsof the blade.

References Cited in the file of this patent UNITED STATES PATENTS AlexOct. 11, Mayne Mar. 11, Young Apr. 8, Prewitt May 12, Jovanovich July 5,Echeverria July 17, Woolf July 17, Lasserre et al. Nov. 20,

FOREIGN PATENTS France Mar. 12,

